Inductor applicable to electric furnaces for metal casting

ABSTRACT

An inductor associated with an electric furnace for metal casting, and provided, where juxtaposed to the tank of the furnace, with a perimetric cavity sealed by refractory material in tamped condition, acting as a safety packing and filling all the inner room of the inductor body and building an embossed step in the jointing zone between inductor and tank.

United States Patent Bolla 1 51 May 23, 1972 541 INDUCTOR APPLICABLE TO 3,249,676 5/1966 Rydinger et al 1 3/26 ELECTRIC FURNACES FOR NIETAL 2,008,732 6/1935 Summey ..l3/30 CASTING FOREIGN PATENTS OR APPLICATIONS [72] Carmen 734,227 7/1955 Great Britain ..285/347 [22] Filed: June 17, 1970 Primary Examiner-J. V. Truhe Assistant ExaminerGale R. Peterson [21] Appl 47o35 Attamey-Michael S, Striker [52] US. Cl. ..l3/26, 13/25 ABSTRACT 3; s g g An inductor associated with an electric furnace for metal cast- 1 o ing, and provided, where juxtaposed to the tank of the fur. nace, with a perimetric cavity sealed by refractory material in tamped condition, acting as a safety packing and filling all the [56] References Cited inner room of the inductor body and building an embossed n- STATES PATENTS step in the jointing zone between inductor and tank.

1,176,842 3/1916 Lukomski ..285/295 X 3 Chins, 2 Drawing figures Patented May 23, 1972 INVENTOR. QmvAuui BOLL-A INDUCTOR APPLICABLE TO ELECTRIC FURNACES FOR METAL CASTING BACKGROUND OF THE INVENTION This invention'relates to an improved, particular inductor, which is perfectly interchangeable and sealable, and adapted for application to induction slot-type electric furnaces for the casting and production of ferrous and non-ferrous metals.

As it is well known, the slot-type electric furnace is essentially constituted of a tank, adapted to contain the mass of the cast metal and a heating apparatus, being normally called inductor.

Both the tank and the inductor are lined with refractory material of a different nature, adapted to the high working temperatures and other metallurgical conditions, in relation to the metals and the casting type to be obtained.

In the normal operation, the refractory lining of the inductor is subject to higher stresses than the tank sheathing, so that it wears more quickly. For an optimum exploitation of the refractory material, it is convenient to proceed with replacement of the inductor only, when the tank is still in good condition.

By the methods known heretofore, said inductor replacement is connected with the difficulty of obtaining a suitable tightness between the new inductor refractory surface and the corresponding old tank surface, as well as the difficulty of constantly good result at each operation.

THE INVENTION Just on the contrary, in the case of the inductor, improved according to the present invention, replacement of the latter is easy and ensures, besides a proper tightness, the exclusion of metal infiltrations at the jointing zone between the inductor and the tank.

Said inductor replacement and sealing operation may be carried out both with the furnace in cold condition and in operating temperature condition.

More accurately said, in the case at hand, provision is made for an improved particular inductor, applicable to electric furnace and interchangeable, showing at its connecting zone to the tank such a configuration as to ensure a suitable sealing of perimetric pattern, adapted to prevent liquefied metal infiltrations.

These and other features of the inductor improved according to the present invention will be better understood with the aid of the figures given on the accompanying drawing.

THE DRAWINGS FIG. .1 represents schematically the inductor, associated with the tank, in the operating position, viewed in a section along a plane, including the axis of the tank and perpendicular to the jointing plane, and

FIG. 2 represents the aforesaid assembly, in a sectional view at the jointing zone as shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring now to FIG. 1, there is shown a tank 1 provided with the refractory lining 2 and an inductor, associated with the tank, at the zone indicated by the sectional line AA and including: the magnetic core 3, the inductive coil 4, the starting metal slot 5, the cooling line 6 (air or water cooling line), the outer envelope 7 and all protecting and insulating means.

The aforementioned parts consist of a protecting jacket 8 made out of nonmagnetic material, placed around the inductive coil 4, a layer of refractory material. 9, disposed immediately inside the envelope 7, the filling consisting of tamped refractory material 10, the entire inner space or room of the inductor body.

As previously hinted, the refractory lining of the jointing zone is completed with a small quantity of refractory mass when the inductor is bolted onto the furnace in its final workin osition.

0 this end, provision is made to build at the refractory lining 10 of the inductors central zone a projecting step or rim 10 such as to form, when the inductor and the tank are correctly positioned relative to each other a radially outwardly open groove filed with refractory mass 11 in tamped condition, designed to act a safety packing.

The mass 11 is locked and tamped so as to show a proper tightness with the aid of a metal structural shape 12, split into four portions, each of them having been installed in its seat upon the insertion and tamping of the refractory mass, relating to the corresponding side of the jointing arrangement between inductor and tank as shown in FIG. 2.

I claim: 7

1. In an electric induction furnace, a combination comprising a furnace tank having an inner lining of refractory material, said inner lining having an annular bottom face; an induction unit having an inner lining and being joined to said tank at said bottom face, said inner lining of said induction unit having an annular top face spaced from and facing said bottom face of the lining of said tank and an inner annular rim projecting upwardly from said top face and abutting against said bottom face so as to form together with said bottom face of the lining of said tank and the top face of the lining of said induction unit an annular radially outwardly open groove; and refractory material in tamped condition filling said groove and thus forming a seal between said top face and said bottom face.

2. A combination as defined in claim 1, and including means confining said tamped refractory material at the outside of said groove.

3. In an electric induction furnace, a combination comprising a furnace tank having an inner lining of refractory material, said inner lining having an annular bottom face; an induction unit having an inner lining and being joined to said tank at said bottom face, said inner lining of said induction unit having an annular top face in part abutting said bottom face of the lining of said tank and in part defining with said bottom face an annular radially outwardly open groove; refractory material in tamped condition filling said groove and thus forming a seal between said top face and said bottom face; and means confining said tamped refractory material at the outside of said groove, said means being constituted by a plurality of metal segments forming a complete enclosure about said tamped refractory material in said groove. 

1. In an electric induction furnace, a combination comprising a furnace tank having an inner lining of refractory material, said inner lining having an annular bottom face; an induction unit having an inner lining and being joined to said tank at said bottom face, said inner lining of said induction unit having an annular top face spaced from and facing said bottom face of the lining of said tank and an inner annular rim projecting upwardly from said top face and abutting against said bottom face so as to form together with said bottom face of the lining of said tank and the top face of the lining of said induction unit an annular radially outwardly open groove; and refractory material in tamped condition filling said groove and thus forming a seal between said top face and said bottom face.
 2. A combination as defined in claim 1, and including means confining said tamped refractory material at the outside of said groove.
 3. In an electric induction furnace, a combination comprising a furnace tank having an inner lining of refractory material, said inner lining having an annular bottom face; an induction unit having an inner lining and being joined to said tank at said bottom face, said inner lining of said induction unit having an annular top face in part abutting said bottom face of the lining of said tank and in part defining with said bottom face an annular radially outwardly open groove; refractory material in tamped condition filling said groove and thus forming a seal between said top face and said bottom face; and means confining said tamped refractory material at the outside of said groove, said means being constituted by a plurality of metal segments forming a complete enclosure about said tamped refractory material in said groove. 